I need some render advice...

[tucker]

Hello everyone.

I have an 18 year old barratt house which has some external render at the front. One area which is between the downstairs and upstairs bay window is blown and has been steadily getting worse.

It now needs removing and re-doing. However, I noticed on the inside of the same area (behind a fitted set of drawers, that the internal plaster board is molding and shows signs of damp.

I took the fitted drawers out for a better look and found the board and plaster was moldy. I removed some of the board and it seems the render in the bay window is onto ply board and they have put a damp proof membrane between the ply and the wooden frame. However, they have also nailed through the membrane all over the place, presumably to attach something to the outside of the ply!

It looks like water has got behind the render and wet the ply, which is allowing damp in and causing the plasterboard to soak up some moisture.

Is it common to render onto ply like this?

What's the correct way for it to be done and for me to make sure it's rectified so it's fully waterproof?

I intend to remove the render myself and re-board with ply and get a plasterer to then do the render.

Any guidance much appreciated.

 

[ant]

they will have nailed the eml (expanding metal lathe) to th ply the render is the sealer so when this goes the water has prob been making its way through sounds like it all needs riping out re ply felt eml and rendered oh and the inside will need to be renewed as well

 

[tucker]

Thanks. So, it's the render that provides the waterproof barrier and not so much the membrane...

I will re-board the inside myself and probably also insulate the timber frame while I am at it. I was a bit shocked to see how exposed the bay area is with no insulation or anything.

Hopefully now got a recommended plasterer coming to have a look Friday at the render and will be getting the inside skimmed once it's sorted.

 

[tucker]

Managed to get sorted.

The eml was poorly attached and had come away from the board. Some water was getting in and over time the eml perished, but the ply board was still sound, just a little stained.

It's been pva'd, new eml properly fitted and re-rendered.

I renewed the inside board and also put kingspan in as there was no insulation. I also used foil backed boards for extra pre-caution and it's now been skimmed, so hopefully it will be good for many years to come....

 

[Gibbo]

hope you put some building paper behind eml